1. Field of the Invention
The present invention relates to a frame assembly and, more particularly, to an adjustable frame assembly for a disposable filtering medium, such as an air filter or insect screen, that may be adapted to cover a desired window opening defined by a double hung or casement window or the like, and to remain in place independently of the position of a window sash.
2. Description of The Related Art
Adjustable frame assemblies for window air filter and especially insect screen media are popular products particularly in high rise residential and commercial buildings not usually fitted with custom screens or combination storm windows. Most prior assemblies, such as the one described in U.S. Pat. 5,312,467, are laterally adjustable frames made of wood and/or metal, attached in a cooperable, sliding engagement that is laterally adjusted to fit most double-hung windows. They are window-mounted by placing the frame assembly's bottom and side edges into the respective bottom and side channels for the lower window sash. The assembly is then held in place by lowering the sash until its bottom edge rests on the assembly's top edge.
Such prior devices also include a permanently installed filtering medium, without having a mechanism for removing used and installing new media. Such prior types of frame assemblies suffer from other significant disadvantages, including sash-mounting. Sash-mounting precludes an efficient and effective means of varying the active air-exchange area of the media without first removing the assembly and placing it inside or outside the sash. In addition, no matter what its placement, but particularly without the sash-mounting, the prior types of filter assemblies have not been firmly secured in place and a tendency to disassociate from its placement with time has heretofore been apparent.
The permanently installed filter media loses efficiency over time due to clogging, corrosion and even washing or vacuuming. However, timely replacement of used media is discouraged by the substantial added cost of having also to replace a fully functioning frame. Finally, the prior cooperable sliding section construction has been known heretofore to add undesirable cost to both the overall manufacturing and commercializing process.
These disadvantages have significantly inhibited the use of adjustable frame assemblies despite their important benefits. It has been found that adjustable frames with filter media provide the most effective, economical, non-mechanical means of reducing indoor air pollution by ventilating with outdoor air that is less likely to harm indoor environment and property with outdoor contaminants such as dirt, dust and pollen.
According to the U.S. Environment Protection Agency's Apr. 1, 1995 "Guide to Indoor Air Quality", (EPA 402-K-93-007, p. 4); "A growing body of scientific evidence has indicated that the air within homes and other buildings can be more seriously polluted than the outdoor air in even the largest and most industrialized cities". On May 26, 1989, Director of the National Institute for Occupational Safety and Health Centers for Disease Control, J. Donald Miller, testified before a U.S. Senate committee, that "As mentioned above, in over half of our indoor air quality investigations, inadequate ventilation was found to be the cause of complaints." The E.P.A.'s August 1989 Report to Congress on Indoor Air Quality, (Vol. 1, EPA 400-1-89-0011, p. 6), adds the following important perspective:
"There was wide agreement among participants at the policy forum that altering ventilation standards and practices should be central to the strategy for controlling and preventing indoor air pollution. Consideration of health should become at least equal, and perhaps paramount, to energy conservation in setting ventilation standards. Ventilation standards could become an effective means of controlling multiple pollutants simultaneously as well as cost effectively."
Public awareness of the seriousness of indoor air pollution problems and the value of ventilation has been heightened by mass media articles, such as the Dec. 1, 1996 N.Y. Times story, "The House Can Make You Sick", that concluded; "Finally, experts say it pays to keep some fresh air coming into the house from somewhere--even if it costs a few dollars more for heating fuel". Public awareness notwithstanding, most people, and especially city dwellers, prefer sealed windows and stale, polluted air to open windows with accompanying dirt, grime "pigeon-pollution" and pollen. Some spend precious energy to simulate fresh air with closed air conditioners that merely recirculate indoor air. And some use screens as inadequate filter proxies.
The typical window screen is useful for keeping many insects and small animals out, but it is not particularly useful for filtering out contaminants. These contaminants include airborne allergens such as pollen, and other airborne pollutants including soot, dust or dirt that may enter the house or apartment from the outside. The troublesome contaminant particles are often thrown into the air by industrial plants and vehicles. Ailments that can be caused, aggravated or triggered by such contaminants include allergic reactions, asthma, etc. As indicated above, at least some elementary testing of air quality is now often recommended and included in house inspections and the sale of expensive and cumbersome air purification systems has grown tremendously.
Various types of frames for holding air filters and window screens have been known heretofore. The filters or screens are typically mounted to a frame which is pre-sized at least in one direction to fit into a particular opening whether it be in an air conditioner unit or other unit requiring air filtering. The filter or screen frames known heretofore have been adjustable in the lateral direction only so as to fit different window widths. However, this type of frame is actually limited to only one fixed air exchange area since the height dimension is fixed and the frame depends upon engagement with the sash along its top to be held in place.
What has been needed heretofore is an adjustable filtering or screening mechanism having a frame assembly and filter media structure which may be configured to the desired air exchange area independently of the area of the frame assembly itself, in contrast to the known mechanism in which the desired opening is entirely and permanently determined by the size of the frame assembly.